Telephone-transmitter



(No Model),

H. G. ALEXANDER. TELEPHONE TRANSMITTER.

N0. 58Z, 513.- Patented May 11, 1897.

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UNITED STATES PATENT OFFICE.

HORACE C. ALEXANDER, OF BONHAM, TEXAS.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 582,513, dated May 11, 1897.

Application filed December 4, 1896- Serial No. 614,440. (No model.)

To all whmn it may concern.-

Be it known that I, HORACE C. ALEXANDER, of Bonham, in the county of Fannin and State of Texas, have invented a new and Improved Telephone-Transmitter, of which the following is a full, clear, and exact description.

This invention relates to transmitters for telephones, and the Object is to provide a simple and effective transmitter of the granulated-electrode type so constructed that the granulated elect rode cannot become displaced from the cell.

I will describe a transmitter embodying my invention and then point out the novel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in both views.

Figure 1 is a plan view of a transmitter embodying my invention with a portion of the diaphragm broken away, and Fig. 2 is a crosssection thereof.

Referring to the drawings, 1 designates a metallic shell having an annular flange 2, provided with perforations through which screws may pass to secure the transmitter to the door of a transmitter-box. The shell is open at its front, and its rear wall has a central opening 3. Arranged within the shell is a carbon disk 4, provided with a central cell 5, which, as here shown, ext-ends entirely through the disk. The disk is also provided with a series of cups or cells 6, and in the several cells is placed a granulated electrode 7such, for instance, as granulated carbon. Arranged on the back of the shell is a block of insulating material 8, and this block is secured in place by means of screws passing through the bottom of the cells 6 and also through the metal back of the shell. From a central plate 9 on the back of the block 8 a post 10 extends through the cells 5, and. to the inner end of the post 10 is secured the diaphragm 11, with which the granulated material 7 contacts. Arranged between the diaphragm and the carbon disk is a layer of soft textile material 12--such, for instance, as fe1tand this soft material is secured to the carbon disk by means of a suitable cement. By cementing the soft material in place .it cannot become crimped or displaced and thus allow the escape of the granulated material in the cells, and this interposed soft material will prevent rattling of the diaphragm.

I do not confine my invention to any particular number of cells in the carbon disk, neither do I limit my invention to the particular meansshown and described for fastening the diaphragm in place, as a main feature of my invention resides in securing the soft material to the carbon disk by means of an adhesive.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A telephonetransmitter, comprising a metal shell open at its front and having a central opening through its rear wall, a carbon disk in the shell having a cell extended through it in line with the opening through the back of the shell, a block of insulating material secured to the back of the shell, a granulated electrode in the cell, a post extended through the cell, a contact-plate in engagement with the rear end of the post, a diaphragm in the shell and having a contact with the post and shell, and a soft textile material between the diaphragm and carbon disk, the said textile material being cemented in'place, substantially as specified.

2. A telephone-transmitter, comprising a metal shell open at its front and having a central opening through its rear wall, a carbon disk in said shell and having a central cell extended through it, and a series of cuplike cells, granulated electrodes in the several cells, a diaphragm having electrical connection with a contact-plate and with the shell, and a soft textile material between the diaphragm and carbon disk and cemented to said disk, substantially as specified.

HORACE O. ALEXANDER.

Witnesses:

JAs. R. MCKINNEY, D. W. SWEENEY. 

